A reappraisal of the role of Gram's stains of tracheal aspirates in guiding antibiotic selection in the surgical intensive care unit.
BACKGROUND
Tracheal aspirate Gram's stains are used to guide antibiotic selection in empiric pneumonia treatment in the surgical intensive care unit (SICU). We questioned whether Gram's stains predict the organism cultured.


METHODS
A retrospective review of prospectively collected data.


RESULTS
Gram's stains correlated with the cultured organism in 284 of 543 (52%) SICU cultures and in 226 of 403 (56%) trauma intensive care unit (TICU) cultures. Gram-negative rod (GNR) stains yielded GNR organisms in 182 of 205 (89%) SICU cultures and in 160 of 176 (91%) TICU cultures. Gram-positive coccus (GPC) stains yielded GPC organisms in 75 of 228 (33%) SICU cultures and in 52 of 149 (35%) TICU cultures. Noncorrelates in the GPC group were predominantly GNRs (185 of 250 (74%)).


CONCLUSIONS
When the clinical decision has been made that empiric antibiotic coverage is necessary, GNR coverage should be instituted regardless of Gram's stain result. The decision to institute GPC coverage needs to be supported by clinical data other than the Gram's stain.
Namias
N
N
Emory University School of Medicine, Atlanta, Georgia 30303, USA.
Harvill
S
S
Ball
S
S
McKenney
M G
MG
Sleeman
D
D
Ladha
A
A
Civetta
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D005260:Female; D005840:Gentian Violet; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D018579:Patient Selection; D010619:Phenazines; D011014:Pneumonia / Q000188:drug therapy* / Q000382:microbiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology*
D000900:Anti-Bacterial Agents; C035863:Gram's stain; D010619:Phenazines; D005840:Gentian Violet